1. Field of the Invention
The present invention relates to a charger that charges a battery to be charged while detecting a temperature of the battery.
2. Description of the Related Art
When a battery is charged, its temperature rises. Particularly, when the battery is close to full charge, its temperature sharply rises. A rise of battery temperature causes deterioration of battery characteristics. In order to prevent deterioration of battery performance, a charger that has a temperature sensor for detecting a battery temperature has been developed (see Japanese Patent Laid-Open Publication TOKUKAI No. 2002-199609 and Japanese Patent Laid-Open Publication TOKUKAI No. HEI 5-30669).
In the charger disclosed in Japanese Patent Laid-Open Publication TOKUKAI No. 2002-199609, a temperature sensor that is inserted in a soft tube is in contact with a surface of a battery pack. The temperature sensor is in thermal contact with the surface of battery through the soft tube and detects its battery temperature. In the charger disclosed in Japanese Patent Laid-Open Publication TOKUKAI No. HEI 5-30669, a temperature sensor is pressed by a coil spring and is thermally coupled to a thermally conductive member of the battery pack. The temperature sensor detects its battery temperature through the thermally conductive member.